Default warning system

ABSTRACT

Apparatus and method for detecting malfunctions in fiber blending equipment and for sounding a warning after the detection of such a malfunction. In the embodiment disclosed below, which is specifically designed for use with fiber equipment of the type whereby a plurality of adjacently mounted weighing pans receive fiber to be blended and, under the control of appropriate electrical circuitry, weigh and dump it upon a conveyor which periodically moves forward to form fiber sandwiches which are then delivered to other equipment, the failure of the relay which controls the conveyor to be activated after a set time greater than the time that the relay remains deactivated during normal operation causes a horn to give an audible indication of malfunctions.

United States Patent 3,659,279 51 Apr. 25, 1972 Wise [54] DEFAULT WARNING SYSTEM [72] Inventor: Dan 5. Wise, Gaston, NC.

[73] Assignee: Fiber Controls Corporation, Gastonia,

[22] Filed: June 27, 1969 [21] Appl. No.: 837,253

[52] US. Cl. ..340/267 R, 177/80 [51 Int. Cl. ..008b 19/00 [58] Field of Search ..340/267, 309.1; 177/80; 317/135,141;307/141,141.4,141.8

[56] References Cited UNlTED STATES PATENTS 2,864,910 12/1958 Wintriss ..340/267 UX 3,030,616 4/1962 Onulak ..340/267 3,073,402 1/1963 Greene et al. ..177/80 3,225,848 12/1965 Wise et a1. ..177/80 3,321,704 5/1967 Mann 340/3091 UX 3,371,254 2/1968 Hagfors ..317/135 3,470,553 9/1969 Hyde ...340/268 Lytton et a1. ..177/80 [57] ABSTRACT Apparatus and method for detecting malfunctions in fiber blending equipment and for sounding a warning after the detection of such a malfunction. In the embodiment disclosed below, which is specifically designed for use with fiber equipment of the type whereby a plurality of adjacently mounted weighing pans receive fiber to be blended and, under the control of appropriate electrical circuitry, weigh and dump it upon a conveyor which periodically moves forward to form fiber sandwiches which are then delivered to other equipment, the failure of the relay which controls the conveyor to be activated after a set time greater than the time that the relay remains deactivated during normal operation causes a horn to give an audible indication of malfunctions.

3 Claims, 1 Drawing Figure DEFAULT WARNING SYSTEM BRIEF DESCRIPTION OF THE PRIOR ART AND SUMMARY OF THE INVENTION The invention relates to a default warning system whereby the failure of blending equipment to operate properly is detected and malfunctions noted by a warning signal such as an audible horn sound.

The textile industry is quite familiar with automatic blending line equipment of the type which forms a continuous fiber sandwich on a moving conveyor such as disclosed and claimed in the Lytton et al U.S. Pat. No., Re 25, 609, and the Wise et al U.S. Pat. No., 3,225,848. Such equipment has been used for many years to sandwich blend varioustypes of textile fibers, both synthetic and natural. Many times, if not most of the time, different bales of fibers, whether they are natural fibers or synthetic fibers, need tobe mixed by such blending equipment in order to give them uniformity. Most synthetic fiber manufacturers and balers of natural fibers recommend mixing different bales of the same type of fibers, since greater uniformity in the product can thereby be obtained. Generally speaking, sandwich blending is effective to prevent streaks in the yarn or fabric manufactured therefrom.

The method and apparatus disclosed in the above mentioned Lytton and Wise patents for effecting such automatic blending employs a plurality of feeders mounted above a single conveyor belt or line. Each type of material to be blended is fed into one of the weigh pans where it is weighed and the flow cut off when the desired amount has been received therein. When all of the weigh pans receiving material for any given blend have weighed the correct amount, the pans are simultaneously dumped onto the halted conveyor belt which then moves forward a short distance and halts until the next dump so as to build up the proper sandwiches on the conveyor At the same time the .pans are refilled and again dumped when all'have received the proper weight of material. Appropriate electrical circuitry, such as disclosed in the above mentioned Lytton and Wise patents, normally controls the feeding and cutting off of the fiber material into the weigh pan and the dumping of the material onto the conveyor at the proper time, as well as the stopping and starting ofthe conveyor after dumping.

The conveyor then delivers the fiber sandwich to appropriate blending or other equipment which mixes the sandwich, or performs any other desirable operation which may be called for. Often theblending system which forms the sandwich is capable of operating at a greater speed than the other equipment to which it delivers the sandwiches, with the result that provision is normally made in the control circuitry which operates the blending equipment to interrupt the blending operation until the equipment receiving the sandwiches signals its readiness for more material. An indication of readiness or non-readiness to receive more sandwiches is normally carried back to control circuitry by operating a switch which is located in that'circuitry, and which is usually termed the Limit Control Switch or LS 1 switch for short. Further, the blending circuitry may be shut down from time to time for maintenance at the end of a shift or for any other reason.

Malfunctions which come about after such restarting by the closure of the pickercontrol switch or LS 1 switch as well as malfunctions which take place in the normal course of filling, weighing and dumping can, if undetected, considerably disrupt operations by producing a large number of sandwiches which are not in the correct ration and which are then processed with undesirableresults and usually considerable waste in time and money. The present invention relates to a simple apparatus and method for use as or with control circuitry for fiber blending equipment which quickly detects such malfunctions, which result both after restarting and during normal operation, and gives an indication such as an audiblehorn sound, so that the malfunction can be corrected before any significant disruption or losses take place.

This is accomplished in the embodiment discussed below by a combination of relays which cause a time delay relay to be activated whenever both the Limit Control Switch LS 1 is closed and the relay which operates the conveyor is deactivated so that the conveyor is not running. The time delay relay is adjusted so that it will close a controlled switch, completing a current path through a born or other indicator, after a delay which is longer than the time the conveyor relay remains deactivated when the system is operating properly. Thus, this simple arrangement not only detects malfunctions which result after the restarting of the system because of the closing of the Limit Switch LS l, but also detects malfunctions which result in the normal course of operation.

Many other objects and purposes of the invention will become clear from the following detailed description of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The FIGURE shows a control circuitry according to this invention for controlling the feeding and weighing of material into a plurality of associated weigh pans and the dumping of these weigh pans onto a conveyor system whereby an indication is given of malfunctions in the system.

DETAILED DESCRIPTION OF THE DRAWINGS Reference is made to the Figure which shows control circuitry suitable for controlling the feeding, weighing and dumping of fiber material in a fiber blending system of the type described above and in the abovementioned Wise and Lytton patents. The circuitry is also very similar to the control circuitry illustrated in Wise U.S. Pat. No. 3,439,838. The operation of the control circuitry shown in the Figure should be apparent from the disclosure of these patents, particularly the Wise U.S. Pat. No. 3,439,838, and these disclosures are explicitly incorporated herein by reference.

As mentioned briefly above, the circuit shown in the Figure controls the feeding of material into a plurality of associated weigh pans of which three W,, W and W are diagrammatically illustrated in the Figure. Selector Switches SW,, SW and SW are also provided to permit operation of less than all of the weigh pans and these switches are further discussed in the abovementioned Wise U.S. Pat. No. 3,439,838. This feeding is normally accomplished by means of suitable electrical motors and three feed motors FM,, FM and F M are also diagrammatically illustrated in the Figure. Assuming that switch LS 1, which is labeled PS in the Lytton et al U.S. Pat. No. 25,360, is closed, indicating a demand for fiber sandwiches, the operation of the circuitry of the Figure will now be briefly described.

After the three weigh pans W W and W have simultaneously dumped material onto the conveyor, which is not shown in the Figure, but which is fully disclosed and discussed in the abovementioned Lytton et a1 and Wise patents, a current path is completed through the conveyor relay CV which then operates a switch (not shown) which causes the conveyor belt to move forward by supplying power to a conveyor motor. This path runs from the alternating current source through onoff switch 10, down lines 12 and 68, through switch 5D,, which is in the illustrated position, through normally open switch WD which is now closed because of the activation of relay WD as explained below, down line 72 to contact C, through switch TD, which is normally in the position shown, and down lines 122, 124, 16, and 14 to the other side of the source. The conveyor belt then moves forward until a Cam Dump Switch 60, which is normally open, engages a member or other structure, mounted on or with the conveyor belt for movement therewith, forcing the Cam Dump Switch 60 closed in the manner disclosed fully in the abovementioned Lytton and Wise patents. The closing of the switch 60 completes a current path through the relay SD via line 58, switch 60, line 62, diode 64, and lines 66, 67, 16, and 14. Relay SD responds immediately to the current flowing through it by shifting the position of switch SD, into connection with contact B and line 71, thus cutting off the current flowing through the relay CV and abruptly stopping the conveyor which is controlled by relay CV. The activation of relay SD also closes switches SD, and 8D,. To insure that relay SD will remain activated even should the conveyor coast past the position closing switch 60, a latching circuit for relay SD is also completed by the closing of switch SD, from line 68 through switch SD,, lines 71 and 73, normally open but now closed switch DIL,, line 74, diode 64, and lines 66, 67, 16 and 14.

At the same time that the conveyor is moving forward, fibers are fed into the weigh pans W,, W, and W, by feed motors FM, and FM, and FM, which are connected to a three phase source as shown by ganged, normally open switches 40, 42 and 44 which are kept closed by activated relays M,, M, and M, respectively, which also control normally open switches 46, 48 and 50 respectively. These relays M,, M, and M, are activated as shown by a current path which runs through closed switch 20, which is a safety switch, line 18, lines 22 and 24, weight switches WS,, WS,, and WS,, each of which remains connected to the empty contact E until the weigh pan with which it is associated has weighed the correct amount, line 32, switch TD, and lines 16 and 14. As each of the weigh pans weighs the correct amount and shifts the WS switch associated with it to the F or full contact, the M relay associated with that weigh pan is deactivated and the switches which that M relay controls are returned to their normal positions. Relays TV,, TV, and TV, are connected in parallel with relays M,, M, and M, and operate trapdoors preventing the feeding of material into the weigh pans when deactivated, as explained in greater detail in the abovementioned Wise and Lytton et al patents. For example, when the weigh pan W has weighed the correct amount of fibers, the switch WS, shifts into connectionwith contact F and line 80, and the relay M, is deactivated, thus opening the switches 40 and 46 which it controls, deactivating motor FM, and cutting off the feeding of fibers into weigh pan W,.

When all of the relays M,, M, and M have been deactivated, switches 46, 48 and 50 will all be open and normally activated relay DIL will then be deactiated, allowing normally closed switch DIL, to close and thus completing a current path through the time delay relay TD via line 75, now closed switch 5D,, line 76, normally closed switch DIL,, diode 77, line 78, and line 14. The activation of time delay relay TD shifts the switch TD, into connection with contact D and line 71 and recompletes a current path through the conveyor relay CV which then causes the conveyor to move ahead again. Likewise, the shifting of switch TD, completes a current path via now closed but normally open switch SD, through all of the dump valve relays DV,, DV,, and DV, which respond by dumping the contents of each of the weigh pans W,, W, and W onto the moving conveyor belt. Normally closed switch TD is opened and normally open switch TD is closed by the activated relay TD with switch TD, completing a latching circuit around the switches DIL, and 8D,, which continues as long as any of the weigh pan switches WS,, WS,, or WS,, are connected to an F contact, indicating a dump has not taken place.

The deactivation of the DIL relay also opens normally open switch DlL,, thus cutting off the current flow through the relay SD which however delays a short time before changing the positions of the switches it controls. After the short period has elapsed, switch SD, opens, thus deactivating relays DV,, DV, and ov,, causing the weigh pans to resume their normal state in preparation for receiving more material. Likewise, as the now empty weigh pans cause their weigh pan switches to move back into connection with the E contacts, the relays M,, M, and M TV,, 'TV, and TV, and DIL are prepared to be reactivated as soon as the switch TD, is reclosed by the deactivation of relay TD.

Like relay SD, the relay TD delays a short period in permitting the switches controlled by it to shift their positions after current through relay TD is cut off. A short time after the relay SD is deactivated opening switch SD, and all of the weigh pan switches WS,, WS, and WS, return to their illustrated positions, the relay TD then pennits all of the switches controlled by it to resume their illustrated positions, thus reactivating relay DIL, relays M,, M, and M and relays TV,, TV, and TV The movement of switch TD, back into connection with contact C and line 72 also allows the current to resume flowing through the relay CV so that the conveyor moves forward again until Cam Dump Switch 60 is again reclosed to activate relay SD and repeat the cycle.

As mentioned briefly above the fiber blending circuitry illustrated in the Figure is frequently capable of operating at a greater speed than other equipment receiving the fiber sandwiches. Accordingly, provision is made to stop the fiber blending equipment automatically if at any time the blending equipment down the line indicates an inability to handle further material. This indication is conveyed to the control circuitry of the Figure by the switch LS 1 which is disclosed in detail in the abovementioned Lytton and Wise patents, and which is opened when it is desired to stop the blending equipment from dumping further material on the conveyor and to stop the conveyor from moving.

The relay WD as shown in the Figure is connected between lines 12 and 16 via the Limit Switch LS I, sometimes called the Picker Switch, so that relay WD remains activated, keeping switch WD closed so long as the switch LS ,1 remains closed. Should switch LS 1 open, indicating no further sandwiches are needed, then relay WD is deactivated opening switch WD,. Opening switch WD, automatically stops the conveyor CV, if it is moving, and prevents the circuitry from dumping the weigh pan contents onto the conveyor after they have been weighed, since switch 60 cannot then be closed. Instead, the weigh pans will weigh the correct amount and then shift the weighing switches WS,, WS, and WS into connection with the F contacts, at which time nothing further will occur since the relay SD has not been activated by the closing of the switch 60 which results from the movement of the conveyor to the correct position. The control circuitry will then simply wait until the switch LS l is reclosed at which time the conveyor will be moved forward again and the contents of the weigh pans dumped in the manner described above after the Cam Switch 60 is closed. 7

If a dump is in progress when the switch LS 1 is closed, i.e. if the relay SD has already been activated, the circuitry will then continue and dump the contents of the weigh pans onto the conveyor in the same manner described above. However, after switches SD, and TD, return to their illustrated positions, the relay CV will not be activated and the weigh pans W,, W, and W, will then fill up in the manner described above but not dump further material onto the conveyor.

With the circuitry shown in the Figure, it is usually possible to predict accurately how long it will take the weigh pans to fill up and activate relay TD after the conveyor has moved the correct distance and activated relay SD. Thus, if the relay CV remains deactivated for a time longer than the time normally required, it can be assumed that a malfunction has occurred and the novel warning circuitry of this invention causes an audible or other indication to be given upon detecting such a condition.

As mentioned above, the relay WD is normally activated, closing both switches WD, and WD,, whenever the switch LS l is closed indicating a demand for the fiber sandwiches. Likewise, the relay WL, which is connected between line 122 and line 16 in parallel with the relay CV, opens its normally closed switch WL, whenever the relay CV is activated. Thus, should switch LS 1 be closed and the relay CV deactivated, a current path is completed through the variable time delay relay WTD via switch LS 1, closed switch WD,, normally closed switch WL,, and line 16. Time delay relay WTD is adjusted so that unless the current path is maintained for a set time greater than the time relay CV should remain deactivated, switch WTD, will not close. If however, current still is passing through relay WTD when the set time after current began flowing through relay WTD elapses, switch WTD is closed, completing a current path from line 12 to line 16 through the horn 130 which then gives an audible indication that a malfunction has occurred.

Likewise, if the LS 1 switch is open and then recloses to signal the equipment to continue supplying sandwiches, the relay WL immediately closes switch WL and the switch WL remains closed as long as the conveyor relay CV remains deactivated. Thus, if the system fails to restart the conveyor within the time limit set by the relay WTD, it is assumed that a malfunction has taken place and the switch WTD is closed to complete the current path to the horn 130 which then announces the malfunction.

It should be apparent that in place of the horn 130 any type of warning or detecting device can be alternatively employed. Such other arrangements might include a light, a signal to a computer or other recorder or any other arrangement.

It should be further apparent that the simple, ingenious arrangement shown in the Figure for detecting defaults is capable of responding to a large number of different malfunctions and further will detect and announce a warning of virtually every problem except conveyor slippage and heater kick-out as the result of overload. Any malfunction which prevents the conveyor relay CV from being energized within the time set on relay WTD, for example 20 seconds, will sound the alarm.

For example, should any of the switches W8 WS or W8 stick in connection with the F contact, either because of a malfunction of the switch or because for some reason the weigh pans W W and W were not dumped such as a faulty relay at TV TV or TV sticking trapdoors, etc., then the relay TD will not be deactivated to permit the relay CV to be reactivated within the time set on the relay WTD, and a ma] function indication will result. Further, if no material is being fed into one of the weigh pans for some reason, such as a malfunction of the feed motor or a lack of material being supplied to the weigh pans, then a dump will not occur within the set time after the relay SD is activated to shift the switch SD and the relay WTD will cause an audible indication. It should be apparent then that this very simple arrangement is thus capable of detecting a wide range of different problems and failures and of responding to those failures by giving an indication which will permit errors to be corrected quickly before the entire fiber blending line is disrupted.

Many changes and modifications of the above example of the invention should be apparent to anyone of ordinary skill in the art. Accordingly, the scope of the invention is limited only by the scope of the appended claims.

What is claimed is: 1. A fiber blending system comprising: a plurality of weighing pans for receiving fibers to be blended, conveyor means beneath said weighing pans, means for weighing the fibers in each of said weighing pans and for dumping the fibers in said pans onto said conveyor means when the weight of fibers in each said pan equals a weight chosen for that pan, means for causing said conveyor means to move after each dumping a given distance, including relay means having a first condition causing said conveyor means to move and a second condition not causing said conveyor means to move, switch means electrically connected to said causing means having a first position disabling said causing means and a second position not disabling said causing means, and means electrically connected to said switch means for indicating a malfunction whenever said switch means is in said second position and said conveyor means remains stopped for longer than a chosen time period, including means for detecting when said relay means is in said first condition so that said conveyor is moving said detecting means including second relay means having a first condition when said switch means is in said first position and a second condition when said switch mean is in said second position, third relay means havrng a first condition when both said first and second relay means are in said first condition and a second condition when both said first and second relay means are not in said first condition; and horn means associated with said third relay means for giving an audible indication when said third relay means remains in said first condition for longer than said chosen time period.

2. A system as in claim 1 wherein said third relay means includes a switch connecting said horn means to a source of electrical energy and means for closing said switch after said third relay means has been in said first condition for said chosen time period.

3. A system as in claim 2 including means to adjust said chosen time period. 

1. A fiber blending system comprising: a plurality of weighing pans for receiving fibers to be blended, conveyor means beneath said weighing pans, means for weighing the fibers in each of said weighing pans and for dumping the fibers in said pans onto said conveyor means when the weight of fibers in each said pan equals a weight chosen for that pan, means for causing said conveyor means to move after each dumping a given distance, including relay means having a first condition causing said conveyor means to move and a second condition not causing said conveyor means to move, switch means electrically connected to said causing means having a first position disabling said causing means and a second position not disabling said causing means, and means electrically connected to said switch means for indicating a malfunction whenever said switch means is in said second position and said conveyor means remains stopped for longer than a chosen time period, including means for detecting when said relay means is in said first condition so that said conveyor is moving said detecting means including second relay means having a first condition when said switch means is in said first position and a second condition when said switch mean is in said second position, third relay means having a first condition when both said first and second relay means are in said first condition and a second condition when both said first and second relay means are not in said first condition, and horn means associated with said third relay means for giving an audible indication when said third relay means remains in said first condition for longer than said chosen time period.
 2. A system as in claim 1 wherein said third relay means includes a switch connecting said horn means to a source of electrical energy and means for closing said switch after said third relay means has been in said first condition for said chosen time period.
 3. A system as in claim 2 including means to adjust said chosen time period. 